1. Field of the Invention
This invention relates to a connecting structure and a processing method for a shielded wire in which a shield terminal is connected to braid at an end portion of the shielded wire.
2. Description of Relevant Art
FIGS. 1A, 1B show a conventional processing method of a shielded wire end disclosed in Japanese Patent Application Laid-Open Publication No. 7-201383. Under this structure, an end portion of a shielded wire 1 is separated to core 2 and braid 3 and a terminal metal (a terminal metal to be connected to an end of the braid 3 is referred to as "shield terminal") 4 is crimped to each of ends of the core 2 and braid 3. Before the terminal metal is crimped to the shield terminal 4, the end portion of the braid 3 is bound by a heat shrinkage tube 5.
However, in the connecting structure described in the aforementioned patent application, in addition to a procedure for peeling the core cover covering the core 2 so as to expose the core 2, a procedure for peeling a long portion of a insulating outer cover 6 covering the braid 3 to expose the braid 3, a procedure for twisting the braid 3 to fit the heat shrinkage tube 5 to the exposed braid 3, and a procedure for passing the twisted braid 3 through the heat shrinkage tube 5 are needed, so that it takes a long time for this connection work. Further, because it is so constructed that the braid 3 does not cover the core cover in a long range, the shielding performance drops.
Therefore, Japanese Patent Application Laid-Open Publication No. 8-78071 has disclosed a structure which enables the braid 7 connect to to the shield terminal 8 easily. Under this structure, as shown in FIGS. 2, 3, the covering of the shielded wire 9 is peeled before connection. After the braid 7 is exposed by peeling the insulating outer cover 10, the braid 7 is folded back toward the insulating outer cover 10 so that it overlaps. After that, an insulating inner cover 11 is peeled so as to expose a core 12.
This processed shielded wire 9 is fixed to a terminal 13 via the insulating inner cover 11 by inserting the insulating inner cover 11 into a holding portion 13a of the terminal 13 and then crimping the holding portion 13a. Further by crimping a connecting portion of the terminal 13, the core 12 is connected to the terminal 13. Then, with this condition, the terminal 13, is inserted into the cylindrical shield terminal 8 and the braid 7 is connected inside the shield terminal 8.
The connection between the shield terminal 8 and braid 7 is carried out by making leaf springs 14, 14 which are folded inside the shield terminal 8 as shown in FIG. 3, into contact with the braid 7 so as to ensure conductivity. In FIGS. 2, 3, reference numeral 15 denotes a housing in which the shield terminal 8 and terminal 13 are inserted, and reference numeral 16 denotes a cap to be fit to an opening end 8a of the shield terminal 8.
Under this connecting structure, it is not necessary to expose the braid 7 in a long range and the procedures for twisting the braid 7, inserting the braid 7 into the heat shrinkage tube, and crimping the shield terminal 8 to the braid 7 are eliminated. Therefore, its work efficiency for the connection has been improved as compared to the connecting structure described first.
However, in this connecting structure, the procedure for exposing the braid 7 by peeling the insulating outer cover 10 of the shielded wire 9 is necessary. This peeling procedure is troublesome and time-consuming.
Further, it is necessary to provide leaf springs 14 inside the shield terminal 8 specially designed for the shielded wire 9 and further the housing 15 for accommodating the shield terminal 8 must be specially designed for the shielded wire 9 and the cap 16. As a result, the entire structure becomes complicated and a large number of parts are required, so that production cost is high.
Further, to avoid a poor contact between the leaf spring 14 and braid 7, a spring load of the leaf spring 14 needs to be set large. However, if the spring load is set larger than required, it becomes difficult to insert the braid 7 in between the leaf springs 14. Further, if the spring load is large, the braid 7 is drawn by the leaf springs 14 so that a poor contact between the leaf springs 14 and braid 7 may occur.